[Elecraft] Proper grounding for P3.

[Don Wilhelm]

David,

You don't have to drill a hole, just connect the bonding strap to any 
screw on the enclosure.
The entire purpose is to conduct the hum, buzz and noise onto the outer 
surface of the enclosure instead of letting it be conducted onto the 
ground plane of the circuits inside.
If you will note, the BNC and other connectors do not connect to the 
enclosure, but the ground points are instead connected to the circuit board.
In the old days, those connectors were mounted on the enclosure and then 
wired (on the inside) to the circuit board - today, the connectors are 
instead mounted directly to the circuit board, and have no electrical 
connection to the outside of the enclosure.  That is the classic "pin 1" 
problem.
In the P3 situation, that can cause spikes from unknown sources in the 
display because of noise pickup on the coax shield.

Remember, this is bonding, not grounding.  Ground is for AC mains and 
lightning protection safety.

Yes, do connect those ground rods to the utility entrance ground with #6 
or larger wire - that is protection for you, your family and pets in 
case of a fault anywhere in the wiring of your house.

73,
Don W3FPR

On 3/29/2018 11:12 AM, David Olean wrote:
> Don, Dave et al,
>
> Thanks for all the tips. I was really just wondering about where to 
> drill holes in the P3, or if it should be bonded at all. I have been 
> doing much reading on removing common mode signals and was happily on 
> my way to achieving that with numerous lossy ferrite chokes at 
> strategic spots.  The idea to daisy chain the bonding wire between 
> "boxes" to minimize ground loops seems like a good one too. I will 
> revise my grounding.  My goal was to make the ham shack as safe as 
> possible for lightning protection, but the impetus for the project was 
> discovering that common mode signals were creeping in on all my 
> beverage feedlines.  There are really two different situations that 
> are being addressed.  Reading ON4UN's book (The latest revision) was 
> an eye opener as far as how common mode signals can mess up a beverage 
> installation. Following his advice, I have made good strides in 
> stripping unwanted noise from my feed lines.  I am bonding my station 
> ground rods with the power entry panel ground as well.  That will  be 
> an expensive undertaking as they are quite far apart. I am not looking 
> forward to making the trench to bury the wire.
>
> Thanks again. I'll bite the bullet, drill a hole in the P3 and hope 
> that it does not interfere with the yet un announced Elecraft P3 
> Cappuccino machine option.
>
> Dave K1WHS
>